Oscar Pistorius arrives at his trial in Pretoria, South Africa, on March 28. / Siphiwe Sibeko, Reuters

by Kim Hjelmgaard, USA TODAY

by Kim Hjelmgaard, USA TODAY

The murder trial of Oscar Pistorius has been postponed until April 7 after the judge in the case said Friday that one of the legal experts assisting her has been taken ill.

The delay in proceedings comes at a point in the trial when Pistorius, 27, was expected to provide testimony as his defense team prepared to begin its case.

"One of my assessors is not well, so this court is not properly constituted," Judge Thokozile Masipa announced shortly after Pistorius arrived in the courtroom in Pretoria on Friday morning.

South Africa does not have a jury system and the verdict in the trial into whether the double-amputee runner shot his girlfriend Reeva Steenkamp last year in an act of premeditated murder will be delivered by Masipa alone. Although two judicial assessors will assist her in reaching the verdict.

The prosecution rested its case on Tuesday after 15 days of accounts that included testimony from Pistorius' neighbors as well as close scrutiny of more than 1,000 text messages sent between the athlete and Steenkamp, a well-known South African model, TV celebrity and law graduate.

The Olympic medal winner - nicknamed the "blade runner" because of his prosthetic limbs - denies deliberately killing Steenkamp, and says instead that he shot her through a bathroom door in a tragic accident when he mistook her for an intruder.

Pistorius faces 25 years to life in prison if convicted of premeditated murder.

As the only witness to what happened in February 2013, Pistorius is "likely" to testify when the trial resumes, his lawyers have said. He is not legally bound to do so.